(Reuters) – Yahoo Inc said yesterday that at least 500 million of its accounts were hacked in 2014 by what it believed was a state-sponsored actor, a theft that appeared to be the world’s biggest known cyber breach by far.
Cyber thieves may have stolen names, email addresses, telephone numbers, dates of birth and encrypted passwords, the company said. But unprotected passwords, payment card data and bank account information did not appear to have been compromised, signaling that some of the most valuable user data was not taken.
The attack on Yahoo was unprecedented in size, more than triple other large attacks on sites such as eBay Inc, and it comes to light at a difficult time for Yahoo.
Chief Executive Officer Marissa Mayer is under pressure to shore up the flagging fortunes of the site founded in 1994, and the company in July agreed to a $4.83 billion cash sale of its internet business to Verizon Communications Inc.